Rail joint



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. Patented Get. 20, 1931 PATENT OFFICE KARL ANDREAS LAGERGREN, 0F STOGKHOLIv'I, SWEDEN RAIL JOINT Application filed September 19, 1929, Serial No. 393,663, and in The present invention relates to a rail joint intended, without impairing the strength of the joint, to prevent or to reduce the occurrence of shocks when a rail. road wheel. passes The invention also has for its object to transfer the bending moment from one rail at a joint to the other, without the longitudinal variations of the rails being prevented on changes in temperature. Furthermore, the invention aims at avoiding or reducing the beating down of the rail head at the joint.

Previous endeavours to solve the present problem were in many instances aimed at providing a bearing surface for the wheel without interruptions, by means of vertical or horizontal blades projecting from the one rail and engaging into'corresponding recesses in the other. However, if these blade joints are examined closely, it will be readily found that none of them offers even a proximately sufficient. strength to withstanc the stresses involved. A number of inventors, frequently suchas have not been skilled in the art, ob-

viously have been of theopinion that the" mere presence of a blade of the type indicated would be sufiicient to-transfer the moment between the rails.

Therefore," the principal and the most difficult problem in the design of the present construction has been to give it sufficient strength and durability. V .4 p

This has been effected by causing a strong stud formed substantially out of the web of the rail, with or without reinforcement by material welded thereon, to engage accurately into a recess provided in the other rail, said recess being limited by an upper projection formed substantially ,by the head of the rail, and a lower projection formed by the base of the rail and a portion of the web, which is likewise reinforced, if required, by welding material thereon. By this arrangement both rail ends are compelled to follow one another at the same level. In order to facilitate accurate adjustment and subsequent adjustment of the rails, without the'necessity of resorting to precision work, one or more wedges of some suitable material, such as tenacious steel of a somewhat lower degree of hard- Sweden October 1, 1928.

ness than that of the rails, may be inserted between the bearing surfaces of the studs or projections. Said wedges may be secured in position laterally, for instance by bending the thinner portion thereof in the hot or cold state. Inasmuch as the upper and lower sur faces of the wedges as well as of all projections are parallel to the longitudinal direction of the rails, the expansion of the rails is not prevented on variations in temperature. If the wedges, which, as above stated, have a somewhat lower hardness than the rails, become worn by the longitudinal changes and deflections of the rails and work loose,' they may be easily tightened up or replaced by new wedges. Trials carried out at a greater private railroad in Sweden'have shown, however, that the wedges have not worked loose by the traflic on a main track, even for a long period of time, where the construction or joint in question has been employed. The maintenance work for these joints thus appears to be small. No danger from the point of view of safety in operation will be incurred if a wedge would happen to work loose, inasmuch as the joint will in such a case function in the ordinary manner, just as if no stud construction were provided, until the wedge in question is again tightened up.

By the rigidity thus imparted to the joints, and by the considerable reduction of the so called joint beating angle resulting from the superior transfer of the moment between the rails and from the'reduced deflection of the rail ends involved thereby, the joint beats or the shocks caused by the wheels passing over the joints will be reduced to a great extent. A further improvement in this respect may be obtained by cutting off the rails obliquely, so that the wheel, which is calculated to bear on a certain width of the top of the rail, will not leave one rail before it has come into contact with the other.

This oblique cut of the rails has proved not to be serviceable in the earlier joint constructions because the rail ends would be beaten down too much by the wheel passing from the one, somewhat deflected rail, up onto the other and this substantially hitting a point l in question,

of the obliquely cut bearing surface of the head of the latter rail.

By obliquely cutting the whole rail profile the disadvantage is involved, however, that the one rail tends to move laterally of the other when the ends are pressed against each other on variations in temperature. To obviate this drawback, the lower portions of both rails may, according to the invention,

be cut at right angles to the longitudinal direction and be made somewhat longer than the upper obliquely cut portions, so that the latter can never get into immediate contact with eachother.

At the trials mentioned hereinbefore it has been found, first, that no shock is produced owing to the said arrangements, when a. wheel passes a rail joint of the construction and, second, that beating down or yielding ofthe material, as occurring for the same reason in the ordinary rail joint constructions, fails to appear.

A consequence of the reduced shocks in the joints will also be that the dynamic stresses on the rails will be smaller than in the ordinary joints.

In order that the calculated stresses shall not be exceeded, joining bolts with corresponding holes in the rails and in the fishplate are placed so thatthe intervening space between the rail ends cannot be great-er than a distance assumed beforehand wlth respect to the longitudinal changes of the rails.

Figure 6 is an end view, corresponding to Figure 3, of a modification.

Provided at the one end of the rail 1 is a projecting. stud 2 formed by milling the rail, said stud 2 consisting substantially of a portion of the rail web and of a smaller portion of the rail head. As will be more clearly seen from Fig. 2, the rail head and the said stud 2 are bevelled ofi obliquely, whereas the lower portion of the rail web and the base of the rail are cut off at right angles to the longitudinal direction of the rail.

In the other end of the rail is a milled recess 3 corresponding to the stud 2, and here,

vtoo, the rail head and the innersurface l of the-recess 3are cut obliquely, whereas the .lower portion of the rail web and the rail 1 base=are cut off at right angles to the longitudinal direction.

In joining two rails, the stud 2 of the one rail will, as shown in Fig. 5, project into the recess 3 in the other rall, so that both rails are fixed 1n position at the same level.

To control the mutual level, wedges 5 and 6 are driven in between the upper and lower bearing surfaces between the stud 2 and the recess 3, the smaller ends of said wedges being bent after the adjustment,-as illustrated in Figs. 3 and 4;, so that the wedges are locked laterally.

As will be seen from Fig. 5, the portions of the rail ends cut ofii perpendicularly to the longitudinal direction are somewhat elongated so that, when these portions bear against each other, a small spacewill be pro vided between the bevelled oif portions, which latter cannot thus get into contact with each other so as to cause a lateral displacement of the rail ends.

Otherwise, the joining is effected in the ordinary way by means of fish-plates and screw connections.

In the modification shown in Figure 6, the base of the rail web is reinforced at the joint by welding material 7 on both sides thereon along seams 8 (shown by short crossed lines).

What I claim is 1. In a rail joint, the combination of a stud formed at one rail end and having upper and lower surfaces extending substantially in parallel to the longitudinal direction of the rails, a recess in the other rail end, adapted to receive said stud to compel both rails to follow one another at the same level, and a wedge or wedges be ween the bearing surfaces between said stud and said recess of the adjacent rail ends to control the mutual level bet-ween the rails.

2. In a rail joint, the combination ofa stud formed at one rail end and having upper and lower surfaces extending substantially in parallel to the longitudinal direction of the rails, a recess in the other rail end,

adapted to receive said stud to compel both rails to follow one another at the same level,

and a wedge or wedges between the bearing surfaces between said stud and said recess of the adjacent rail ends to control the mutual level between the rails, the rail ends being cut off obliquely in a manner known per se.

3. In rail joint, the combination of a stud formed at one rail end and having upper and lower surfaces extending substantially in parallel to the longitudinal direction of the rails, a recess in the other rail end, adapted to receive said studto compel both rails to follow one another at the same level, the upper portion of the rail profile being cut off obliquely, while the lower portion thereof is i cut off at right angles to the longitudinal directionof the rail, and the said perpendicularly cut portions of the adjacent rail ends are elongated to prevent the obliquely cut portions from contacting witheaeh other.

4. In a rail joint, the combination of a stud formed at one rail end and having upper and lower surfaces extending substantially in parallel to the longitudinal direction of the rails, a recess in the other rail end, adapted to receive said stud to compel both rails to follow one another at the same level, and a wed e or wedges between the bearing surfaces between said stud and said recess of the adjacent rail ends to control the mutual level between the rails, the upper portion of the rail profile being while the lower portion thereof is cut off at right angles to the longitudinal direction of the rail, and the said perpendicularly cut portions of the adjacent rail ends'are elongated to prevent the obliquely cut portions from contacting with each other.

5. In a rail joint, the combination of a stud formed at one rail end and having upper and lower surfaces extending substantially in parallel to the longitudinal direction of the rails, 'a recess in the other rail end, adapted to receive said stud to compel both rails to follow one another at the same level, and a wedge or wedges between the bearing surfaces between said stud and said recess of the adjacent rail ends to control the mutual level between the rails, the web of at least one of the adjacent rails being rein forced at the thereon.

In testimony KARL joint by welding material ANDREAS LAGERGREN.

cut off obliquely,

whereof I aifix mysignature. 

